JP2001113138A - Production method of immersion type membrane cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of an immersion type membrane cartridge enhanced durability to aeration. SOLUTION: A resin-made filter plate 22A is cooled at a specified temperature and a filter membrane 22B is arranged to cover the surface of the filter plate 22A in a state contracted by cooling, and the filter membrane 22B is stuck or welded to the filter plate 22A at a water stopping part S formed on the whole periphery along the peripheral part of the filter plate 22A to fix, and the filter membrane 22B is applied a tensile force by elongating the filter plate 22A under a temperature to be used and is stretched.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a submerged membrane cartridge, and more particularly to a technique for manufacturing a membrane cartridge mounted on a solid-liquid separation device used in a human waste treatment or a combined treatment septic tank.

[0002]

2. Description of the Related Art As a conventional solid-liquid separation apparatus, for example, there is an immersion type membrane separation apparatus as shown in FIGS. Figure 5
In FIG. 7, a membrane separation device 21 has a plurality of flat membrane cartridges 22 and an air diffuser 23 for ejecting a membrane cleaning gas from below the cartridges 22 arranged inside a case 24. The case 24 is formed so as to be divided into a membrane case 25 and a diffuser case 26 so that the entire amount of the membrane surface cleaning gas ejected from the diffuser 23 enters the membrane case 25.

The membrane cartridge 22 has a filtration membrane 22B disposed on both surfaces of a filter plate 22A made of ABS resin.
B is attached to the filter plate 22A by ultrasonic welding or an adhesive at a water stop portion S on the periphery thereof. Filter plate 22
A permeate flow path is formed between A and the filtration membrane 22B and inside the filter plate 22A, and a permeate outlet 22C communicating with the permeate flow path is formed at the upper end edge of the filter plate 22A.

Each membrane cartridge 22 is provided with a permeate outlet 2
The tube 27 is connected to a water collecting pipe 28 via a tube 27 connected to the 2C, and a permeated liquid outlet pipe 29 for extracting a membrane permeated liquid is connected to the water collecting pipe 28.

[0005]

In the above configuration, when the membrane separation device 21 is used in an activated sludge treatment facility, the membrane separation device 21 is immersed in an activated sludge mixed liquid in an aeration tank to diffuse air. In a state in which aeration air is jetted from the device 23, organic matter and nitrogen in the raw water are treated with activated sludge.

[0006] The activated sludge mixture is gravity filtered by the membrane cartridge 22 using the head in the tank as the driving pressure (the suction filtration is also possible by interposing a suction pump in the permeate outlet pipe 29). The permeated liquid permeating through the membrane surface of No. 22 is led out of the tank through a permeated liquid outlet pipe 29 as treated water. At this time, the bubbles of the aerated air ejected from the air diffuser 23 and the upward flow generated by the bubbles flow through the narrow flow path (width of 5 to 10 mm) between the mutually adjacent membrane cartridges 22 to form a membrane. The membrane surface of the cartridge 22 is cleaned to prevent the separation function from deteriorating, thereby preventing the membrane separation device 21 from malfunctioning.

As described above, when the membrane separation device 21 is used, the membrane cartridge 22 is exposed to the upward flow by the aerated air, so that the filtration membrane 22B is moved upward by the upward flow. Because this upward flow is a turbulent flow derived from bubbles,
As shown in FIG. 7, the filtration membrane 22B rushes toward the upper water stop S while waving, and the welding strength of the filter membrane 22B deteriorates, and the water stop S
, Fatigue fracture easily occurs, which affects the life of the membrane cartridge.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a method of manufacturing a submerged membrane cartridge capable of improving durability against aeration.

[0009]

According to a first aspect of the present invention, there is provided a method for manufacturing a submerged membrane cartridge, comprising: cooling a resin filter plate at a predetermined cooling temperature; A filter membrane is placed over the surface of the filter plate in a contracted state, and the filter membrane is fixed to the filter plate by bonding or welding to the filter plate at a water stop portion formed over the entire periphery along the periphery of the filter plate. Are provided at the operating temperature to give a tensile force to the filtration membrane to thereby tension the filtration membrane.

According to a second aspect of the present invention, there is provided a method of manufacturing a submerged membrane cartridge according to the present invention, wherein a filtration membrane is placed in tension on a resin filter plate so as to cover the surface thereof, and is provided over the entire periphery along the periphery of the filter plate. In the formed water stop portion, the filtration membrane is fixed to the filter plate by bonding or welding to fix the filtration membrane in a tensioned state. In the method for manufacturing a submerged membrane cartridge according to the present invention according to claim 3, the resin filter plate is cooled at a predetermined cooling temperature,
The filter membrane is placed in a tensioned state covering the surface of the filter plate in a state contracted by cooling, and the filter membrane is adhered or welded to the filter plate in a water stop portion formed over the entire periphery along the periphery of the filter plate. The filter is fixed, and the filter plate is stretched at the operating temperature to apply a tensile force to the filtration membrane to thereby tension the filtration membrane.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. The immersion type membrane cartridge in the present embodiment is used for an immersion type membrane separation device,
Since the basic structures of the immersion type membrane separation device and the membrane cartridge are the same as those described above with reference to FIGS. 5 to 7, the same members are denoted by the same reference numerals and description thereof is omitted.

A method of manufacturing the membrane cartridge 22 according to the present embodiment will be described below with reference to FIGS.
The filter plate 22A has a linear expansion coefficient of 0.08 to 0.095 mm.
/ M ・ ℃ ABS resin, width 490mm × length 10
It has a shape of 00 mm x thickness of 6 mm, and extends about 0.1 mm in the longitudinal direction when the temperature rises by 1 ° C. This filter plate 22A
Is cooled at a predetermined cooling temperature of, for example, 5 ° C. or lower, and is in a state of contraction by cooling. A filtration membrane 22B made of an organic film is arranged on both surfaces of the filter plate 22A, and the filtration membrane 22B is fixed to the filter plate 22A by ultrasonic welding or an adhesive at a water stop portion S on the periphery thereof.

Since the membrane cartridge 22 is used at a water temperature of 15 ° C. or more in, for example, an activated sludge tank, the filter plate 22A extends according to the temperature difference between the temperature at the time of use and the temperature at the time of cooling. It extends about 1 mm or more. Due to the extension of the filter plate 22A, a tensile force acts on the filtration membrane 22B, and the filtration membrane 2B
2B becomes nervous. As another method for manufacturing the membrane cartridge 22, there is a method shown in FIGS. In this method, the filter membrane 22B is covered with a resin filter plate 22A to cover the surface.
Is arranged, and a tensile force is applied to the filtration membrane 22B to keep it in a tensioned state. The filtration membrane is a polyester nonwoven fabric (thickness 0.1
(0.15 mm) coated with an organic film agent on both sides, and has an elongation of 10% due to stretching. However, if the film is stretched too much, the pore size of the film may be deformed, which may affect the filtration performance. is there. For this reason, the filtration membrane 22B is maintained in a tensioned state extended by about 2 to 5%. next,
In the water stopping portion S formed over the entire periphery along the periphery of the filter plate 22A, the filter membrane 22B is fixed to the filter plate 22A by an adhesive or ultrasonic welding, and the filter membrane 22B is held in a tensioned state.

As a method of manufacturing the membrane cartridge 22, there is a method of combining the above-described methods. In this method, the filter plate 22A made of resin is cooled at a predetermined cooling temperature of 5 ° C. or less. A filtration membrane is arranged so as to cover the surface of the filter plate 22A contracted by the cooling, and a tension is applied to the filtration membrane 22B to maintain the tension state. In this state, the filter membrane 22B is fixed to the filter plate 22A by bonding or welding at the water stopping portion S formed over the entire periphery along the peripheral edge of the filter plate 22A.

With this configuration, in addition to the initial tension, the filtration membrane 22B receives a tensile force due to the extension of the filter plate 22A, and the filtration membrane 22B is maintained in a tensioned state. The membrane cartridge 22 manufactured as described above is used by being mounted on the membrane separation device 21 in the activated sludge treatment facility. In this use, the bubbles of the aerated air ejected from the air diffuser 23 and the upward flow generated by the bubbles flow through the narrow flow path (5 to 10 mm width) between the adjacent membrane cartridges 22. The membrane surface of the membrane cartridge 22 is cleaned to prevent a decrease in the separation function, thereby preventing the membrane separation device 21 from malfunctioning.

At this time, the filtration membrane 2 of the membrane cartridge 22
2B receives an urging force upward due to the upward flow, but since the filtration membrane 22B is in a tension state, the filter film 22B is not pushed to the upper water stopping portion S while waving and waving, and is exposed to the turbulent upward flow. Always maintain a flat film surface. For this reason, unlike the related art, fatigue breakage does not occur in the water stopping portion S, and the life of the membrane cartridge 22 can be extended. Also,
Since the filtration membrane 22B always maintains a flat membrane surface, the upward flow uniformly acts as a scavenging flow on the entire membrane surface, and the cleaning effect is enhanced.

When the membrane cartridge 22 is used for a certain period, it is immersed and washed. In this immersion cleaning, sodium hypochlorite or oxalic acid solution is injected into the membrane cartridge 22 in the reverse direction from the permeate side, and the filtration membrane 22B is immersed in a chemical solution for cleaning. For this reason, the filter membrane 22B is spot-welded to the filter plate 22A inside the water stop portion S as necessary. Thus, it is possible to prevent the filtration membrane 22B from expanding due to the injection of the chemical solution, reduce the elongation of the filtration membrane 22B, suppress the upward movement of the filtration membrane 22B due to the upward flow and bubbles, and extend the life of the membrane cartridge 22. it can.

[0018]

As described above, according to the present invention, the filter membrane is always kept in tension during use by the force applied during the manufacture of the membrane cartridge. The filtration membrane is not lifted, can always maintain a flat membrane surface, does not cause fatigue destruction in the water stop portion S, can extend the life of the membrane cartridge, and can always maintain a flat membrane surface. By maintaining it, the upward flow uniformly acts as a scavenging flow on the entire film surface, and the cleaning effect is enhanced.

[Brief description of the drawings]

FIG. 1 is a schematic view illustrating a method for manufacturing a membrane cartridge according to an embodiment of the present invention.

FIG. 2 is a schematic view showing a membrane cartridge manufactured in the same embodiment.

FIG. 3 is a schematic view illustrating a method for manufacturing a membrane cartridge according to an embodiment of the present invention.

FIG. 4 is a schematic view showing a membrane cartridge manufactured in the same embodiment.

FIG. 5 is a schematic view showing an immersion type membrane separation device.

FIG. 6 is a front view showing a conventional membrane cartridge.

FIG. 7 is a schematic view showing a state of use of a conventional membrane cartridge.

[Explanation of symbols]

 21 membrane separator 22 membrane cartridge 22A filter plate 22B filtration membrane 23 air diffuser

Continued on the front page (72) Inventor Tatsuya Uejima 2-47, Shikitsu-Higashi 1-chome, Namiwa-ku, Osaka-shi, Osaka (72) Inventor Masaaki Nagano 1-2-1-2, Shikitsu-higashi, Naniwa-ku, Osaka, Osaka No. 47 Kubota Co., Ltd. (72) Inventor Yasunobu Okajima 2-47 Shikitsu Higashi 1-chome, Naniwa-ku, Osaka-shi, Osaka No. 47 Inventor Yukio Fujiwara Yukio Fujiwara 1-chome, Shikitsu-Higashi, Naniwa-ku, Osaka, Osaka No. 47 No. 47 F-term in Kubota Corporation (Reference) 4D006 GA02 HA41 HA91 HA93 JA07B JA07C JA22Z JB04 JB07 KA31 KA44 KB22 KC03 KC16 KD16 KD24 MA03 MA06 MA31 MA40 MC48X PA01 PB08 PC62 PC65 4D028 AB00 BC17

Claims (3)

[Claims] 1. A filter plate made of resin is cooled at a predetermined cooling temperature, and a filter membrane is arranged so as to cover the surface of the filter plate that has been contracted by cooling, and formed over the entire periphery along the periphery of the filter plate. A immersion type membrane cartridge characterized in that a filtration membrane is adhered or welded to a filter plate at a water stop portion to be fixed, and the filter plate is stretched at an operating temperature to apply a tensile force to the filtration membrane to tension it. Manufacturing method. 2. A filter membrane is placed in tension on a resin filter plate so as to cover the surface thereof, and the filter membrane is adhered or welded to the filter plate at a water stop portion formed over the entire periphery along the peripheral edge of the filter plate. A method for producing a submerged membrane cartridge, comprising fixing the filtration membrane in a tensioned state. 3. A filter plate made of resin is cooled at a predetermined cooling temperature, and a filter membrane is placed in a tensioned state so as to cover the surface of the filter plate contracted by cooling so as to cover the surface thereof. An immersion characterized in that the filter membrane is adhered or welded to the filter plate at the water stop portion formed over the periphery and fixed thereto, and the filter plate is stretched at the operating temperature to apply a tensile force to the filter membrane to cause tension. Manufacturing method of mold membrane cartridge.